The present invention relates to an optical fiber connector for connection between optical fibers.
For a better understanding of the present invention, description will be made at first as regards a first and a second conventional optical fiber connector.
Referring to FIG. 1, the first conventional optical fiber connector is of a plug-adapter-plug type for connecting plugs 30 and 30xe2x80x2 via an adapter 40. The plug 30 comprises an outer member 31, an optical fiber aligning base plate 32 having a number of V-grooves, a pair of optical fiber guides 33 each having a number of V-grooves, an optical fiber aligning guide 34, a rear shell 35, a pair of plate springs 36 provided at both sides of the rear shell 35 for pressing the optical fiber aligning guide 34, and an optical fiber bunch 37.
The optical fiber aligning base plate 32 and the optical fiber guides 33 are disposed in the optical fiber aligning guide 34. The optical fiber bunch 37 is formed by aligning optical fibers 37A in parallel. The optical fibers 37A are inserted from a side of the rear shell 35, then pass on the V-grooves of the optical fiber aligning base plate 32 and between the V-grooves of the pair of optical fiber guides 33 so as to be projected from an end surface 31A of the outer member 31. The plug 30xe2x80x2 has the same structure as the plug 30.
The adapter 40 comprises a pedestal holder 41, a pair of blocks 42 provided at both sides of the center of the holder 41, a micro-sleeve retaining base plate 43 having a number of V-grooves, a number of micro-sleeves 44 parallelly arranged on the micro-sleeve retaining base plate 43, an aligning plate spring 45 symmetrically provided on an upper surface of each of the blocks 42, and a guide holding plate spring 46 symmetrically provided on a side of each of the blocks 42.
When the plugs 30 and 30xe2x80x2 are fitted to the adapter 40 from both sides thereof, the optical fibers 37A and 37xe2x80x2A are inserted into the corresponding micro-sleeves 44 from both sides thereof so that end surfaces of the optical fibers 37A and 37xe2x80x2A abut each other to be connected.
Referring now to FIGS. 2 to 4, the second conventional optical fiber connector is of a plug-receptacle type for connecting a plug 50 to a receptacle 70. The plug 50 comprises a plug frame 60, an optical fiber bunch 52 formed by parallelly aligning a number of optical fibers 52A, a first base plate 53 having a number of V-grooves, a second base plate 54 having a number of V-grooves, a V-groove guide 55, a clamping presser plate 56, contractile tubes 57 for covering the optical fibers, a rear shell 59, a pair of plate springs 58 provided at both sides of the rear shell 59 for pressing the V-groove guide 55, and an optical fiber fixing base plate 61.
The first and second base plates 53 and 54 are disposed in the V-groove guide 55. Since the first and second base plates 53 and 54 and the V-groove guide 55 cooperatively align the optical fibers 52A, they are generically called an optical fiber aligning member 65.
The receptacle 70 comprises a shell 75, a V-groove guide 73 having a ]-shape in section, a V-groove base plate 72 disposed in the V-groove guide 73 and having a number of V-grooves, a number of micro-sleeves 71 aligned on the V-groove base plate 72, optical fibers 77 received in the corresponding micro-sleeves 71, and a presser plate 76.
The plug 50 is fitted to the receptacle 70 and then fixed by a fixing spring 78. The plug frame 60 is attached to the V-groove guide 73 so that the optical fibers 52A are inserted into the micro-sleeves 71. In the micro-sleeves 71, end surfaces of the optical fibers 52A come in abutment with end surfaces of the corresponding optical fibers 77 so as to be connected to each other.
In the first conventional optical fiber connector, it is necessary that the ends of the optical fibers 37A be projected beyond the end surface 31A of the outer member 31 as shown in FIG. 1A. On the other hand, in the second conventional optical fiber connector, the ends of the optical fibers 52A may be retreated from an end surface 60A of the plug frame 60 as shown in FIG. 3. However, since the optical fibers 37A and 52A are exposed to the exterior both in the first and second conventional optical fiber connectors, they are highly liable to be damaged.
Further, since the optical fibers 37A and 52A in the plugs 30 and 50 are subjected to positioning in the aligning members 44 and 71 of the adapter 40 and the receptacle 70 and then connected to the optical fibers 37xe2x80x2A and 77, respectively, it is necessary that the optical fibers 37A and 52A be projected from an end surface 34A of the optical fiber aligning guide 34 and an end surface 55A of the V-groove guide 55 at least by about 2 to 3 mm.
For example, for realizing a multi-fiber connector of 0.25 mm pitch, the accuracy required for positioning between each optical fiber in a plug and an aligning member of an adapter or receptacle is about 0.1 mm (0.05 mm on one side).
When performing the positioning between each optical fiber and the aligning member, a positional error is caused in a pitch direction or in a direction perpendicular to the pitch direction due to dimensional dispersion of the respective portions of the optical fiber connector. This positional error has been dealt with by improving the dimensional accuracy of the parts, thereby resulting in increased producing cost of the optical fiber connector.
It is therefore an object of the present invention to provide an optical fiber connector which has a structure for protecting an optical fiber and is capable of facilitating positioning between the optical fiber and an aligning member thereby to reduce the producing cost thereof.
It is another object of the present invention to provide an optical fiber connector which can stably perform positioning between an optical fiber and an adapter.
It is another object of the present invention to provide an optical fiber connector which can easily select bending or non-bending of an optical fiber.
Other objects of the present invention will become clear as the description proceeds.
According to one aspect of the present invention, there is provided an optical fiber connector for connecting an optical fiber to a counterpart optical fiber by abutting a connecting end of the optical fiber against a connecting end of the counterpart optical fiber in a given direction while bending of the optical fiber is caused at a portion thereof, the connector comprising an outer member which holds a portion of the optical fiber remote from the connecting end of the optical fiber, an aligning member which is held by the outer member so as to be movable in the given direction and in a direction opposite to the given direction, the aligning member positioning the connecting end of the optical fiber, and an urging member which urges the aligning member in the given direction, the aligning member being moved, when connecting the optical fiber to the counterpart optical fiber, in the direction opposite to the given direction against an urging force applied by the urging member so that the connecting end of the optical fiber is projected from the aligning member.
It may be arranged that a connecting-side end surface of the aligning member is located on the same plane as a connecting-side end surface of the outer member before connecting the optical fiber to the counterpart optical fiber.
It may be arranged that a connecting-side end surface of the aligning member is projected from a connecting-side end surface of the outer member before connecting the optical fiber to the counterpart optical fiber.
It may be arranged that the connecting end of the optical fiber is retreated from an connecting-side end surface of the aligning member before connecting the optical fiber to the counterpart optical fiber.
It may be arranged that the urging member is made of metal.
It may be arranged that the urging member is made of resin.
It may be arranged that the urging member has a shape of a torsion coil.
It may be arranged that the urging member has a shape of an expansion coil.
It may be arranged that the urging member has a plate shape.
It may be arranged that the optical fiber connector further comprises an adapter to be fitted to the outer member, wherein the adapter comprises an aligning member for receiving therein the connecting end of the optical fiber for alignment thereof and, upon fitting of the outer member and the adapter, the adapter moves the aforementioned aligning member in the direction opposite to the given direction against the urging force applied by the urging member.
It may be arranged that the adapter is guided by an inner periphery of the outer member when moving the aforementioned aligning member in the direction opposite to the given direction.
It may be arranged that the optical fiber connector further comprises a fitting piece which is attached to the outer member so as to contact the optical fiber to control the bending of the optical fiber.
It may be arranged that the fitting piece is detachable relative to the outer member.
It may be arranged that the fitting piece has an elastic member which contacts the optical fiber.
According to another aspect of the present invention, there is provided an optical fiber connector comprising a first optical connector plug and an adapter for connecting the first optical connector plug to a second optical connector plug, the first optical connector plug comprising an outer member which holds an optical fiber, a first aligning member which performs positioning of the optical fiber at a connecting-side end of the outer member, and a spring which urges the first aligning member in a first direction, the adapter comprising a second aligning member which receives a connecting end of the optical fiber for alignment thereof, the second aligning member being moved, upon fitting of the first optical connector plug and the adapter, along an inner periphery of the outer member to a given position in a second direction opposite to the first direction and then pushes the first aligning member to slide it in the second direction, so that the optical fiber in the first connector plug is inserted into the second aligning member for connection.
According to still another aspect of the present invention, there is provided an optical fiber connector comprising a first and a second optical connector plug each having an optical fiber and an adapter for connecting the first and second optical connector plugs via the adapter, wherein a contact force between an end surface of the optical fiber of the first optical connector plug and an end surface of the optical fiber of the second optical connector plug is obtained from a buckling load caused by bending of at least one of the optical fibers, each of the first and second optical connector plugs comprising a clamp member which firmly holds a first portion of the optical fiber other than a tip portion thereof including the end surface, a first outer member which holds the clamp member, and a fitting piece which is detachably held by the first outer member, the adapter comprising an aligning member which slidably holds the tip portion of the optical fiber, and a second outer member which holds the aligning member, the fitting piece having one of a first shape which presses a second portion of the optical fiber between the first portion and the tip portion when the fitting piece is held by the first outer member, and a second shape which does not press the second portion of the optical fiber when the fitting piece is held by the first outer member.